New York, Nov 30 : After several studies linked high vitamin D supplementation with reduced Covid-19 effects, now researchers from Penn State University in the US, to study whether vitamin D could help people ward off or reduce symptoms caused by coronavirus. The research team, including one of Indian-origin, have received nearly $241,000 from the National Institutes of Health (NIH) for research on how vitamin D regulates the immune system in the gastrointestinal tract. Cantorna said the addition of two key collaborators in the study are virologist Troy Sutton and Girish Kirimanjiswara, associate professor whose research focuses on immunology and infectious diseases. "Patients with acute respiratory infections have been shown to be vitamin D deficient, and vitamin D supplements have been touted as being useful in high doses for preventing seasonal influenza," Cantorna said. "Meanwhile, the emergence of SARS-CoV-2 has generated interest in the potential of high-dose vitamin D supplements to prevent and treat severe disease associated with the Covid-19 pandemic," Cantorna added. The research group has shown that vitamin D plays an important role in maintaining health in the gastrointestinal tract. Higher levels of vitamin D reduce susceptibility to inflammatory bowel disease and Crohn's disease, as well as gut and lung infections in animals and people. However, too much vitamin D can be harmful. Cantorna noted that the local and systemic inflammation caused by SARS-CoV-2 infection is not well understood, and controlling such inflammation may improve outcomes for COVID-19 patients. Although low vitamin D status has been associated with acute respiratory diseases, research has not confirmed a causal relationship. "We don't yet fully understand the mechanisms underlying the effects of vitamin D in the lung or how vitamin D regulates host immunity to viral infection," she said. "These significant knowledge gaps have hindered the development of interventions and accurate messaging that include vitamin D for the treatment and prevention of respiratory disease," she noted. Using mouse and hamster models, the research team will test whether supplemental vitamin D treatments will limit viral replication and inflammation in the lung leading to protection against severe SARS-CoV-2 infection. "We plan to determine the effects, dose and timing of possible vitamin D interventions in infected animals," Cantorna said. "Because SARS-CoV-2 has been shown to infect the gastrointestinal tract, the benefits of vitamin D might include regulation of gastrointestinal immunity as well as lung immunity," the author wrote. /IANS